1. Field of the Invention
The present invention relates to a sheet feeding device, an image forming apparatus, and an image forming system.
2. Description of the Related Art
High productivity and superior stability are required for sheet feeding devices that are used in image forming apparatuses, such as copiers or printers, and that feed sheets to an image forming unit, and a friction separation method using a sheet feeding roller or an air separation method using air blowing is used. Among them, in a sheet feeding device that makes a separation due to air blowing, separation air is blown to a sheet that is suctioned onto a conveyance belt due to a negative pressure so that the second and subsequent sheets are separated, whereby the sheets are conveyed one by one.
Furthermore, some of the sheet feeding devices, which make a separation due to air blowing, are provided with a floating restricting member that restricts the lifting position of the sheet that is floated due to blowing of separation air, thereby restricting lifting of the sheet.
Japanese Patent No. 4677354 discloses a sheet delivering device that is provided with a floating restricting member to release the suctioned sheet while preventing air from escaping, the provided floating restricting member pushes both ends of a sheet with respect to a width direction such that the central part of the sheet with respect to the width direction is floated over the entire area in a sheet feeding direction due to air that is blown by an air blowing unit and an auxiliary air blowing unit, and the floating restricting member is attached such that it is rotatable in a vertical direction.
However, in conventional sheet feeding devices, the floating restricting member makes it difficult to perform operations to place sheets or remove sheets. Furthermore, although the floating restricting member is rotatable as described in Japanese Patent No. 4677354, the floating restricting member is always ejected and it interferes with sheets being moved in or out. Furthermore, with the floating restricting member, sheets cannot be placed within the rotation range, especially, the downward rotation range; therefore, there is a limitation on the load capacity of sheets such that the upper end of the loaded sheets does not fall within the downward rotation range of the floating restricting member. Moreover, when sheets are placed, the floating restricting member is brought into contact with the sheets, the hands, or the like; therefore, the working space is limited, and the sheets or the device is sometimes damaged depending on the direction or the strength of the contact.
In view of the above-mentioned conventional problem, there is a need to provide a sheet feeding device in which the provided floating restricting member does not interfere with an operation to place sheets or an operation to remove them, does not cause any damage to the device or sheets, or does not limit the load capacity of sheets.